Module 6 Review

Question 1

Which of the following is an example of an object imaged at the correct distance but is lateral to its proper location?

1. Refraction
2. Propagation speed error
3. Side lobes
4. A and C
5. All of the above

Answer 1

3. Refraction and side lobes

Question 2

What assumption accounts for the artifact imaged at the correct distance but lateral to its proper location?

Answer 2

1. Sound travels in a straight line
2. Echoes originate from points along the main beam axis

Question 3

What artifacts can cause objects to be displayed in improper location or incorrect sizes, or both?

Answer 3

1. Propagation
2. Refraction

Question 4

Which statement is correct speed error artifacts?

1. If the propagation speed is greater than 1.54 mm/usec, the display will place the reflector closer to the transducer
2. If the propagation speed is greater than 1.54 mm/usec, The display will place the reflector further from the transducer
3. If the propagation speed is less than 1.54 mm/usec, the display will place the reflector closer to the transducer
4. If the propagation speed is less than 1.54 mm/usec, the display will place the reflector further from the transducer
   E. A and D
   F. B and C

Answer 4

E) A and D

Question 5

What category of artifact does edge shadow belong to?

Answer 5

Refraction

Question 6

When does edge shadowing occur?

Answer 6

When structures are curved and larger than the beam width

Question 7

Focal enhancements is due to what?

Answer 7

Increased intensity at the focal zone

Question 8

Focal enhancement is defined as what?

Answer 8

False brightening of the image at the focal zone

Question 9

Enhancement is caused by what?

Answer 9

A weakly attenuating structure

Question 10

An example of enhancement can be seen beneath what?

Answer 10

A cyst and a bile in the gallblader

Question 11

Mirror image artifacts are a variant of reverberation, T/F?

Answer 11

True

Question 12

When a strong Specular reflector is located in the scan plane, which of the following artifacts is likely to occur?

Answer 12

Mirror image

Question 13

Which of the following statements relates to comet tail artifact?

1. Associates with the presence of a collection of gas bubbles
2. Beams that propagate from a single element in directions different from the primary beam
3. Reverberations that appear as equally spaced discrete echoes
4. Appearance of false debris in an echo free space

Answer 13

3. Reverberations that appear as equally spaced discrete echoes

Question 14

From the following examples, which would NOT cause a comet tail artifact?

1. Biopsy needle
2. Gas bubble s
3. Intrauterine contraceptive device
4. Thin layers of calcium

Answer 14

2. Gas bubbles

Question 15

Grating lobes are caused by areas of energy angled outside the main beam. Which of the following is a solution to resolve this artifact?

1. Decreasing spacing between elements
2. Increasing spacing between elements
3. Subdicing
4. Apodization
5. A and C and D
6. B and C and D

Answer 15

5. A and C and D

Question 16

Grating lobes occur in ________ transducers and are seen as linear echogenic bands or sheets in ______ structures

Answer 16

Array, anechoic

Question 17

Beam width perpendicular to the scan plane causes what type of artifact?

Answer 17

Section thickness

Question 18

The fact that a beam, as it passes through tissue has some non-zero width perpendicular to the scan plane describes the results of __________ artifact

Answer 18

Section thickness

Question 19

Which modes can range ambiguity occur with?
1. 2D
2. Pulsed doppler
3. Colour follow doppler
4. A and C
5. All of the above

Answer 19

5. All of the above

Question 20

Which of the following may cause a range ambiguity artifact?

1. Use of an increased doppler angle
2. Increased PRF
3. Pulsed emitted before the previously received pulse
4. B and C
5. All of the above

Answer 20

4. B and C

Question 21

Which of the following best describes refraction

1. A Back and forth reflection of part or all of a sound beam between two strong reflectors
2. A change in the direction of propagation of sound wave transmitted across a interface where the speed of sound varies
3. A manifestation of increased echo signal amplitudes
4. A loss of echo signals from distal structures due to attenuation

Answer 21

2. A change in the direction of propagation of a sound wave transmitted across a interface where the speed of sound varies

Question 22

Which of the following will NOT produce a shadow?

1. Calcified plaque
2. Air in the biliary duct
3. True cyst
4. Gallstone
5. C and D

Answer 22

True cyst

Question 23

Which of the following best describes shadowing?

1. Absorption
2. Attenuation
3. Penetration
4. Propagation
5. Reverberation

Answer 23

Attenuation

Question 24

If axial resolution is 2 mm and multiple parallel structures are located 4 mm apart, what will happen to the appearance of the structures?

Answer 24

Structures will be visualized at the their real distance and size

Question 25

If axial resolution is 4 mm and multiple parallel structures are located 2 mm apart, what will happen to the appearance of the structures?

Answer 25

Structures may merge and appear as a single object

Question 26

Ring down artifacts are most likely caused by what?

Answer 26

The presence of collection of gas bubbles

Question 27

In reverberation, subsequent reflections are _________ than previous ones.

Answer 27

Weaker

Question 28

The multiple reflections, in reverberation, are placed beneath the real reflector at separation intervals _________ the separation between the transducer and the real reflector.

Answer 28

Equal

Question 29

What impact does a smaller lateral resolution have on the image?

Answer 29

Image enhancement

Question 30

What will improve lateral resolution?

Answer 30

Reducing the beam diameter

Question 31

How will the reflectors deep to a structure that has a speed of sound greater than 1540 m/s appear?

Answer 31

Closer to the probe

Question 32

How would one correct for artifacts related to lateral resolutions?

Answer 32

Scan in the near zone

Question 33

Which of the following is the best way to reduce the clutter in a colour image?

Answer 33

Increase the filter

Question 34

Which of the following is the result of an odd angled strong reflector? 1. Mirror image 2. Edge shadow 3. Refractive duplication 4. Refractive mail position

Answer 34

1. Mirror image

Question 35

Which of the following could be used to correct mirror imaging in a spectral trace? 1. Move the baseline 2. Turn down the 2D gain 3. Turn down the spectral gain 4. Change the operating frequency

Answer 35

Turn down the spectral gain

Question 36

Which of the following artifacts is the results of gas bubbles? 1. Comet tail 2. Ring down 3. Grating lobes 4. Reverberation

Answer 36

Ring down

Question 37

Which of the following may occur when the spectral gain is set to high? 1. Aliasing 2. Decreased EDV 3. Decreased resistive index 4. Over estimation of the PSV

Answer 37

Over estimation of the PSV

Question 38

Which of the following artifacts is due to the assumption that sound travels at 1540 m/s?

Answer 38

Speed error

Question 39

Which of the following has the biggest impact in reducing reverberation? 1. Harmonics 2. Reduce gain 3. Reduce TGC 4. Increase the persistence

Answer 39

Harmonics

Question 40

Which of the following artifact can be useful in diagnosis a calculus? 1. Shadowing 2. Enhancement 3. Reverberation 4. None of the above

Answer 40

Shadowing